In Calistoga, firefighters on front line snuff the spread...

2of19Firefighter Kevin Weaver from Station 1 in Petaluma keeps an eye on a flare up on Lovall Valley Road as crews continue to monitor several wildfires near Sonoma, Calif., on Friday, October 13, 2017. Emergency personnel were deployed to the perimeter of several fires as the threat of gusting winds had them worried that the fires would grow overnight.Photo: Carlos Avila Gonzalez / The Chronicle

3of19A firefighter walks through brush while looking for flare ups outside Robert Louis Stevenson Park near Calistoga, Calif., on Saturday, October 14, 2017. Emergency personnel were deployed to the perimeter of several fires as the threat of gusting winds had them worried that the fires would grow overnight.Photo: Carlos Avila Gonzalez / The Chronicle

4of19A Cal Fire truck and two water tenders sit stationed in Robert Louis Stevenson Park as firefighters continue to monitor several wildfires near Calistoga, Calif., on Saturday, October 14, 2017. Emergency personnel were deployed to the perimeter of several fires as the threat of gusting winds had them worried that the fires would grow overnight.Photo: Carlos Avila Gonzalez / The Chronicle

5of19Firefighters walk balk to their truck after checking a hotspot inside Robert Louis Stevenson Park near Calistoga, Calif., on Saturday, October 14, 2017. Emergency personnel were deployed to the perimeter of several fires as the threat of gusting winds had them worried that the fires would grow overnight.Photo: Carlos Avila Gonzalez / The Chronicle

6of19A firefighter carries a water hose to put out a fire during along the Highway 29 Friday, Oct. 13, 2017, near Calistoga, Calif. Firefighters gained some ground on a blaze burning in the heart of California's wine country but face another tough day ahead with low humidity and high winds expected to return. (AP Photo/Jae C. Hong)Photo: Jae C. Hong, Associated Press

7of19Two firefighters watch for spot fires Friday, Oct. 13, 2017, near Calistoga, Calif. Firefighters gained some ground on a blaze burning in the heart of California's wine country but face another tough day ahead with low humidity and high winds expected to return. (AP Photo/Jae C. Hong)Photo: Jae C. Hong, Associated Press

10of19The sun rises over a smoke-filled mountain Friday, Oct. 13, 2017, near Calistoga, Calif. Firefighters gained some ground on a blaze burning in the heart of California's wine country but face another tough day ahead with low humidity and high winds expected to return. (AP Photo/Jae C. Hong)Photo: Jae C. Hong/AP

11of19Ali Pehzadpour, left, talks in an abandoned downtown Calistoga, with Marshall Hayman, right, who lost home to the fire, after a mandatory evacuation was called for the entire town in Calistoga, Calif., on Wednesday, October 11, 2017. The Napa and Sonoma valleys continue to be under threat from several fires not yet under control and growing fears that strong winds might worsen the situation.Photo: Carlos Avila Gonzalez, The Chronicle

12of19An officer with the Napa County District Attorney's office ties a piece of caution tape on a mailbox to indicate they've searched a property on Petrified Forest Road after a mandatory evacuation was called for the entire town in Calistoga, Calif., on Wednesday, October 11, 2017. The Napa and Sonoma valleys continue to be under threat from several fires not yet under control and growing fears that strong winds might worsen the situation.Photo: Carlos Avila Gonzalez, The Chronicle

13of19A Cal Fire firefighter uses a hand tool as he monitors a firing operation while battling the Tubbs Fire on Oct. 12, 2017 near Calistoga, Calif. At least thirty one people have died in wildfires that have burned tens of thousands of acres and destroyed over 3,500 homes and businesses in several Northern California counties. Photo: Justin Sullivan, Getty Images

14of19Cal Fire firefighter Brandon Tolp uses a drip torch during a firing operation while battling the Tubbs Fire on Oct.12, 2017 near Calistoga, Calif. At least thirty one people have died in wildfires that have burned tens of thousands of acres and destroyed over 3,500 homes and businesses in several Northern California counties. Photo: Justin Sullivan, Getty Images

15of19Firefighters try to extinguish a house fire during the Tubbs Fire on October 12, 2017 near Calistoga, California. At least thirty one people have died in wildfires that have burned tens of thousands of acres and destroyed over 3,500 homes and businesses in several Northern California counties. (Photo by Justin Sullivan/Getty Images)Photo: Justin Sullivan/Getty Images

16of19A CalFire chief runs past burning grass during a firing operation while battling the Tubbs Fire on October 12, 2017 near Calistoga, California. At least thirty one people have died in wildfires that have burned tens of thousands of acres and destroyed over 3,500 homes and businesses in several Northern California counties. (Photo by Justin Sullivan/Getty Images)Photo: Justin Sullivan/Getty Images

17of19Firefighters try to extinguish a house fire during the Tubbs Fire on October 12, 2017 near Calistoga, California. At least thirty one people have died in wildfires that have burned tens of thousands of acres and destroyed over 3,500 homes and businesses in several Northern California counties. (Photo by Justin Sullivan/Getty Images)Photo: Justin Sullivan/Getty Images

18of19CalFire firefighters monitor a firing operation as they battle the Tubbs Fire on October 12, 2017 near Calistoga, California. At least thirty one people have died in wildfires that have burned tens of thousands of acres and destroyed over 3,500 homes and businesses in several Northern California counties. (Photo by Justin Sullivan/Getty Images)Photo: Justin Sullivan, Getty Images

19of19Firefighters try to extibguish a house fire during the Tubbs Fire on October 12, 2017 near Calistoga, California. At least thirty one people have died in wildfires that have burned tens of thousands of acres and destroyed over 3,500 homes and businesses in several Northern California counties. (Photo by Justin Sullivan/Getty Images)Photo: Justin Sullivan, Getty Images

The winds had been promised for days. About 2 a.m. Saturday, they finally arrived in Calistoga, scattering dried leaves across Highway 29 — the road that led up to Mount St. Helena, the road that fire crews would do anything to stop the Tubbs Fire from reaching.

It was the moment they had been waiting for.

With the fire still burning beyond the 35,270-acre swath of destruction it had inflicted on Napa and Sonoma counties, killing at least 19 people in its path, nature had them beat in pure brawn.

But firefighters weren’t competing on strength alone. They wanted to outsmart the blaze.

Fire tankers flanked by large trucks carrying thousands of gallons of water had been on the road all day. They ran hoses into valleys and up peaks, watering everything they could reach. The hope was that the damp ground would prevent anything that caught fire from spreading. That it would stop the fire from jumping too close to town.

After sundown, the sky grew quiet. Airplanes and helicopters that had been dropping water and fire retardant went back to their bases.

A small army of firefighters and police was all that stood between the fire’s uncertain path and the storied town of Calistoga. They would hold the line. They would defend the city and those that lay to its south: St. Helena, Oakville, Yountville and, eventually, Napa.

Although Calistoga remained under a mandatory evacuation order issued Tuesday, a handful of residents remained. Mayor Chris Canning had walked around on Wednesday, imploring them to leave, but some, city officials said, were just too stubborn to listen.

The Tubbs Fire started about 9:45 p.m. Sunday off of Highway 128 and Bennett Lane in Calistoga and spread rapidly into Sonoma County, leveling an estimated 2,834 homes in Santa Rosa, 16 miles away. Over the past several days, firefighters had begun to stem the growth of the blaze.

The cool and dry weather Friday helped. The calm air gave firefighters a window of time to hit the fire hard with ground and air suppression. By Saturday it was 44 percent contained, up from 10 percent on Thursday.

To maximize their reach in the early hours of Saturday, fire crews spread themselves out. Every half mile from town to the Mount St. Helena trailhead about 7 miles up the winding road sat an engine. The trucks, filled with several firefighters, sat in driveways and turnouts, motor on, ready to go.

Cal Fire had dispatched 12 trucks to patrol the area Friday night, looking for flying embers — anything that might catch. At the top of the ridge, a long hose continued to pump water into the hill’s most vulnerable areas.

California Parks Ranger Scott Struckman was stationed there with them, acting as the state’s eyes and ears, ready to report any changes in weather, fire or both.

Struckman, who at about 2:30 a.m. was on the 15th hour of his 19-hour shift, pointed to a bright orange glow through the trees.

“There goes a flare-up,” he said.

Small, glowing embers dotted the darkened line of conifers, each a small fire flickering in the night. Occasionally one would grow stronger, red flames rising.

Marissa Lang covers the intersection of technology and culture for the San Francisco Chronicle, focusing on how the tech industry and technology itself influence and reshape the Bay Area, its people and communities. She covers Twitter, Facebook and the influence of social media, diversity in tech, and the rise of fake news. Marissa joined the Chronicle in 2015. Previously, she covered City Hall for the Sacramento Bee, criminal justice and same-sex marriage for the Salt Lake Tribune and breaking news for the Tampa Bay Times. Born and raised in New York City, Marissa feels the most comfortable in bustling metropolises and is interested in issues of diversity and social justice. Se habla español.